


Solving for Time

by Tarlan



Category: Eureka
Genre: Alternate Universe, Angst, Bodyswap, Community: trope_bingo, M/M
Language: English
Status: Completed
Published: 2013-03-17
Updated: 2013-03-17
Packaged: 2017-12-05 12:54:29
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,871
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/723529
Author URL: https://archiveofourown.org/users/Tarlan/pseuds/Tarlan
Summary: <blockquote class="userstuff">
              <p>An experiment gone wrong sends Jack into an alternate universe where he discovers the solution for saving someone he can finally admit that he loves.</p>
            </blockquote>





	Solving for Time

**Author's Note:**

> Mentions canon relationships.  
> Written for **trope_bingo** Round one - prompt: bodyswap

It wasn't the first time someone had body swapped in this town, Jack thought, recalling the Jo Lupo-Julia Golden fiasco that he'd fortunately missed because he was being tested at the time. Then there was that incident that had his mind body-hopping with Fargo, Zane and Allison, but at least they'd all lived in the same universe, or time stream or whatever Fargo wanted to call it. Except, technically, maybe the return from 1947 was also a form of body swap because they'd ousted the minds of the original Carter, Allison, Fargo, Jo and Henry when they returned to the present in a different timeline. Except body swap implied that the other guys went into their bodies, which would mean that there was a Carter running around in his original body back in their original Eureka. Or maybe they'd swapped into some other version of them from a completely different timeline just as he was swapped...

Jack shook his head because thinking about all this convoluted time and body swapping stuff was making him lose the will to live. He concentrated instead on his present predicament. Namely, the fact that he was no longer inhabiting his _own_ body in any time line... stream... alternate universe... whatever.

This was... He frowned. Whatever this was, it was wrong in the most creepy way possible because in his time line or universe, Nathan Stark was dead. _This_ was a dead man's body. A dead man that was currently in the middle of a conference call to some, no doubt, very important people, who were all starting to look very uncomfortable as the silence lengthened.

Calling on old memories from all the many times he'd interrupted Stark during one of his conference calls, he plastered on a charming smile - or what he sincerely hoped was a charming smile rather than that patented smirk or sneer that he most remembered.

"My apologies. Something's come up. Perhaps we can rescheduled the rest of the meeting for another time."

Without waiting for an answer, Jack's, or rather Stark's hand reached out to cut off the video feed. Jack rolled back his shoulders and stood, smoothing down the expensive suit material before stepping into the private washroom that Stark had never permitted him to enter even when he was covered head-to-toe in goo. 

_No. Use the employee washroom, Carter._

Stark's washroom was his private inner sanctum, and it was luxurious. There was a spare suit hanging up just inside the door, and a shower stall in the corner. No wonder Stark had always looked so good so quickly, even after the worst disaster.

It took a moment to work up the courage to look into the full length mirror, but when he did he felt his heart stutter with the pain of loss. Reaching up, he stroked his own cheek and let his fingers slide along the bearded jaw line and down the side of his throat. He'd had fantasies of doing that while his Stark was alive, along with a lot of other touches that had filled him with both guilt and embarrassment long before Stark's death.

Moving all the way forward, he stopped just a foot away from the mirror, staring into eyes that seemed almost blue in some lights but green in others. He touched the soft lips, recalling those dreams where he had given into temptation and kissed the egotistic bastard, if only to shut him up and make Stark see him as something more than just an expendable moron in a Sheriff's uniform, if only for a moment.

For all his risk taking, Jack had never found the courage to step up and tell Stark that as much as he had loved flirting with Allison, it was nothing compared to how he had felt for the sarcastic scientist. Competing for her affection had always been more about Stark than Allison, and it had taken until the moment he watched Stark dissolve into pieces of light for him to realize he'd waited too long.

It occurred to him that he had been granted a second chance to look into those blue-green eyes and say everything that he had held back over the years through denial or simple cowardice.

"I loved you." He felt the sting of tears. "I was in love with you. I still am. And I hate you for dying on me. For leaving me before I could..."

Leaning over the sink, Jack ran the tap and splashed water on his face. He took several calming breaths, feeling the air filling Stark's lungs.

"So why are you still alive while my Stark is dead," he asked his reflection, feeling a surge of hatred for this universe or whatever because Stark was still alive here.

Returning to Stark's office, he accessed the computer and pulled up a date that was forever etched into his mind - the day Stark died. He felt sick when he realized the reason why Stark was alive was because another man had synced time in Stark's place. It was this universe's Jack Carter who had sacrificed himself to save their universe.

Pushing up from the chair, he walked out of Stark's office, ignoring Fargo's confused, guilt-ridden and fearful look and his sudden babbling - at least that had stayed the same in both universes. He headed down to the memorial walkway, which had become one of his own haunting places in Global for when he needed to think. Jack hadn't truly expected to find his own picture hanging on the wall in place of Stark, and yet he was still bitterly disappointed when he found it wasn't there. Sinking down onto the stone bench seat that ran the length of the walkway, Jack stared into the small water grotto opposite while he idly played with the wedding band around his finger. Several Global scientists walked by, casting him a sideways glance but otherwise ignoring him as if it wasn't uncommon to see him there, and he didn't look up as the doors opened again.

"Nathan?"

Startled by the sound of his own voice, Jack looked up to see himself - Jack Carter - moving quickly towards him, clad in the familiar Sheriff's uniform. Lost for words, he was even more surprised when Carter sat down beside him and grabbed his arms, staring hard into his face. His eyes were wide and blue, and filled with concern.

"You okay? Fargo said you left in a hurry."

"I'm..." He couldn't help the relief pushing out the confusion, knowing he hadn't died and left Zoe all alone in this universe when she needed him most.

Carter grinned and leaned in, pressing his lips against Jack's, and the shock rippled through him as Stark's body reacted as if being kissed by this other version of himself was both familiar and welcome. He felt Carter pull back, eyes narrowed but lips still curved into a smile.

"Are you sure you're okay?"

"Yes. I've got a lot on my mind. Just a little tired," he added for good measure, hoping he could fool himself.

The smile became a smirk as Carter leaned in again and nuzzled his neck, whispering seductively, "Well, I did keep you _UP_ most of the night."

The innuendo wasn't lost on Jack but, fortunately, Carter's cell phone sounded. Carter pulled back with a sigh, turning away slightly as he answered the call, giving Jack a moment to collect himself.

"Yeah, Vincent. I'll be right there." Carter disconnected the call and gave Jack an apologetic smile. "Got to go. See you at home later?" he asked softly.

Jack nodded, deliberately relaxing into the gentle pressure of Carter's lips against his, and watching as Carter stood up and walked away. He looked good in this universe, whatever, and happy. He glanced down at the wedding band and wondered if his assumption that Stark had married Allison was wrong after all. The public kissing and the reference to 'home' implied that he was with this Jack Carter, but it was the love shining in Carter's eyes that told him they were together in every sense of the word.

His lips still tingled from the kiss and he touched them, finding it weird that he now knew exactly how it would have felt for Stark if they had ever kissed.

Realization struck. If this Carter had sacrificed himself then, somehow, they had managed to bring him back, which meant it was possible to bring his Stark back. He strode quickly back to his office, aware of the longer strides from Stark's long legs eating up the distance easily. As he past Fargo he called out.

"Fargo. No interruptions."

"Yes, Doctor Stark."

The computer responded to his thumb and retina scan, and immediately pulled back up the file on the time loop incident. Jack knew the answer had to be in here somewhere. He started reading, hoping he'd be able to find something that he could give to Henry, Zane and Fargo in his own universe that could bring his Stark back. When he found screens of mathematical equations, his heart sank until he realized he already knew part of it. Some of it was Leo Weinbrenner's formula, and other parts came from Walter Perkins' tachyon formula. All he had to do was concentrate on the new stuff, and he picked another nursery rhyme and began to sing the equation softly under his breath. 

He was halfway through the final page when his mind went blurry then blank.

"No, no, no! Not now!"

The world came back into focus inside the Time Maintenance laboratory deep in the bowels of Global. In front of him was a white-board scrawled with equations in a strangely familiar handwriting, and in his hand was a marker pen. Under his breath, he sang along the lines already on the board and then began to write furiously before the memory faded.

When he reached as far as he had memorized, Jack slammed his hand against the white-board, silently praying it would be enough.

"Nathan?"

Jack frowned and turned, shocked to find Henry, Fargo and Zane standing several feet behind him, watching him quietly.

"Henry?"

Henry's eyes narrowed and he stepped forward. "Jack?"

He nodded before turning back to the white-board. "I couldn't get the rest."

Henry squeezed Jack's shoulder. "It'll be enough, my friend. Nathan said we could solve it if he could just get enough of it written down before he swapped bodies back with you." The warmth in his voice caused Jack to look at him. "He left much sooner than he hoped but it looks like he needn't have worried."

Henry was glancing back over the untidy scrawl of Jack's writing, and Jack was gently pushed aside when Zane and Fargo joined him.

****

Nathan blinked rapidly as his office came back into focus. He glanced down at the windows open on his desk, eyes widening when he saw the pages of formula that he'd desperately been trying to write onto a white-board only seconds earlier.

"FARGO!"

Fargo rushed in. "Doctor Stark?"

"I want a list of all projects associated with quantum leaping. And Fargo, send the list to my tablet. I'm going home."

He turned away before Fargo could question him, not wanting to explain right now. Instead, what he wanted more than anything was to see Jack. He hit the speed dial and only relaxed once he heard Jack's voice.

"You okay? You seemed a little out of sorts earlier."

Nathan smiled as Jack's voice washed over him. "I'm fine. I'm heading home. Can you get away early too?"

"Yeah. Andy can hold the fort. Are you sure you're okay?"

He grinned at the concern in Jack's voice. "Just tired."

As soon as he entered the bunker, Nathan discarded his jacket and loosened his tie as he asked SARAH for a whiskey; he drank half in one swallow, placing the glass aside when the door opened for Jack. Stalking across the floor, Nathan barely waited long enough for Jack to take off his gun belt before he had Jack in his arms and was soundly kissing him. He felt the vibration from a moan of appreciation as Jack deepened the kiss, arching into the hands that worked under his shirt to slide across his skin.

Jack pulled away, staring at him hungrily with eyes darkened with desire.

"Quite some welcome home," he whispered hoarsely, and Nathan smiled into the next kiss as his fingers made quick work of unbuttoning the uniform shirt. He pushed the shirt off Jack's shoulders, heedless of where it landed.

Shoes were toed off and their remaining clothing discarded as they kissed and stripped their way up the stairs to their bedroom. Nathan felt Jack go pliant beneath him as he pushed him onto the bed, wondering how it was possible to love Jack even more as Jack simply let him take what he needed, opening himself to Nathan. Nathan's slicked fingers pushed into Jack, quickly preparing him with well practiced movements, knowing exactly what Jack liked. He felt Jack arch up as his fingers found his prostate.

"God! I'm so ready for you, Nathan," Jack whined, one muscular leg wrapping around Nathan's waist to open himself up further. Nathan kissed him hard and dirty before lining up and pushing in.

As always, he felt his chest tighten in pleasure at the sweet tightness of the hot, slicked channel, feeling that amazing heat along the whole length of him as he slowly pushed in to the hilt. He paused for a moment, reveling in the feel of Jack all around him, and in the scent and taste as every sense was filled with pleasure from this man.

By now, Jack would normally be bearing down on him, forcing him to start moving, impatient for the sweet slide of Nathan's cock inside him but Jack seemed to sense that Nathan needed more than this tonight. He waited quietly, hot breath panting against Nathan's neck, and catching at the back of his throat when Nathan pulled out a fraction and slid back, repeating his movement with increasing force until he was slamming hard into Jack, tagging Jack's prostate on every thrust. And Jack took it all, holding him tight and letting him use his body, until he felt Jack tighten beneath him, muscles straining and head falling back in a silent cry as warmth flooded between them.

Feeling overwhelmed by how much he loved Jack at this moment, Nathan buried his face against Jack's hair as he came hard, deep inside of Jack, with his body trembling from the sheer intensity of his need for Jack.

It took several minutes before he stopped shaking, yet Jack never complained once about Nathan's weight pressing him into the bed. He simply waited with his arms tight around Nathan until Nathan had gathered his control and moved slightly to one side, taking his weight off Jack's smaller body.

"So what brought that on?" Jack asked as a hand slowly stroked down Nathan's back.

It took a moment before Nathan could answer. "Body swap."

"Huh?"

Nathan shifted until he could look Jack in the face. "I swapped bodies with a Jack Carter from another quantum universe."

Jack stiffened, eyes darting away for a moment.

"Jack?"

"So... that wasn't you in the Thatcher Memorial Walkway earlier?" His eyes widened as Nathan shook his head. "Oh God! I kissed myself!"

Nathan raised an eyebrow.

"In your body!" He insisted.

"Really." Nathan wasn't certain if he should be annoyed or not though, technically, it had been his lips that Jack had kissed.

"No wonder you... he... seemed a little..." Jack sighed and relaxed back, idly painting designs through the quickly drying semen smeared across his stomach. Nathan grabbed his hand and sucked in one semen-coated finger, licking it clean, enjoying the way Jack's eyes glazed over as if this was the most erotic thing he'd ever experienced.

Nathan sighed as well. For a moment he wondered what it would be like to have never held Jack in his arms, or had him naked in his bed. He wondered how it would be to have never tasted the clean sweat of Jack's skin, the bittersweet tang of his semen, or the sweetness of his lips as they made love. 

The other Nathan Stark had died before he realized what he was missing, and the other Jack had lost his Nathan before he could make that same discovery.

Nathan's thoughts returned to that fateful day when Jack had sacrificed himself to stop the time loops and save the universe. Watching Jack dissolve into a billion shards of light particles had stripped away the last of his denial. He had called off the wedding permanently and had worked tirelessly for weeks searching for a way to bring Jack home. As soon as Jack materialized he had wasted no time gathering him into his arms and soundly kissing him. He hadn't let go of him since that day - metaphorically speaking - eventually placing a ring on Jack's finger to formally declare their relationship to the rest of the world.

His finger played with the similar band around his own finger.

The difference between the universes was Nathan's understanding of the quantum and temporal physics involved - something the other universe had lost when Nathan made that sacrifice instead of Jack. He recalled Jack's memories of those weeks trapped outside of time, of the cold and emptiness of his existence that had lasted - admittedly - only a fraction of the real time, and he knew he could not condemn his alternate self to that fate. It was fortunate that the Henry in that alternate universe had believed him but he had left it too late, pulled back into his own body before he could give Henry everything he needed to bring their Nathan Stark home. Now he could only hope that the other Jack Carter who had inhabited his body had found a way to take some of that knowledge back with him, even if it was sung in a child's nursery rhyme like that last time.

There was nothing more he could do for the other Nathan and Jack unless he could figure out what had made them swap bodies in the first place and then duplicate the results. He had a feeling, though, that it was nothing that had occurred in this universe. Until Fargo sent him that list, all he could do was hold on tight to his Jack and say private thanks for being given the chance to love the man now dozing quietly in his arms.

****

Jack watched as the rest of the equations formed on the white-board while Zane, Henry and Fargo bickered over each addition. Although he hadn't found time to memorize the rest, he recognized certain patterns and pointed them out even though it was all meaningless to him.

Two weeks after the body swap incident, they all stepped back from the white-board and stared hard at the complicated lines of numbers and squiggles.

"You think it will work?" Fargo asked, and Jack could see the hope filling his eyes.

Jack looked from one genius to the next, seeing beyond the love of mathematics and science to the core of their reasons for wanting this to work. Stark... Nathan had meant something to each of them; a friend, mentor, father-figure. Of all of them, Jack knew he should have had the least good reason for wanting Nathan back, especially as Nathan had planned to marry Allison on the day he ' _died_ '. Instead, several years later, Jack had married Allison only to separate from her within a year when they realized that love wasn't enough for either of them.

At least he and Allison had separated on good terms and had remained the best of friends, even if she had taken up with Grant since then.

"Jack?"

They had figured out what had caused the body swap but any attempt by Doctor Miroir to replicate the experiment had failed miserably. Eventually Henry had put it down to some unknown variable.

_"It could have been anything, Jack. The time of day, the atmospheric conditions, another experiment running simultaneously that affected the outcome of the original experiment."_

All three had focused back on the half-completed temporal equations, and now they believed they had the answer. Certainly it looked like the pages of notes he had seen on Nathan's computer screen in that alternate universe, but he couldn't be positive. He was no mathematician, and no genius. Jack sighed and nodded, realizing that there came a time when you simply had to hope for the best.

"Let's do it."

Henry grinned and slapped Jack on the back, but Jack could tell from the tightness around his eyes that he was worried this would not work. They all stepped back behind the control panels except for Jack, who found he had gravitated back to the spot where he had been standing on the day Nathan disappeared.

Nothing happened at first, then very slowly he saw the first glints from light particles dancing in the air near the top of the chamber. The lights began to grow brighter, swirling round and round until something began to take shape. Patches of darkness formed amidst the light, taking on a semblance of material and flesh. He saw the flash of metal from a wristwatch, with dark hairs curling over the band, and then the face began to rebuild in front of him; the dark growth of bristles, the warm almost-olive skin, and dark curls. Jack saw the arch of an eyebrow appear, followed by those beautiful blue-green eyes, and lastly, that rare smile that Nathan had aimed at him in the seconds before his disappearance.

For a moment everything was frozen, and then Nathan blinked, dark eyelashes fluttering as the smile faded.

With trembling fingers, Nathan reached for the inner lock on the chamber and released it, letting the door swing open as he stepped outside. Jack shuffled a few steps forward, closing the distance between them, his eyes locked on Nathan's. His lips began to tingle in memory of that kiss from another Jack Carter in another universe, and he felt his head tilting back as Nathan moved unsteadily towards him until they were barely inches apart.

"Jack?" Nathan whispered.

Breathing hard with fear and elation, Jack recalled the pain of losing Nathan, and the long nights spent with regrets filling his heart and mind. All he knew for certain was that the Nathan Stark in another universe had loved his Jack Carter so it was possible that this Nathan felt the same way for him. Taking the chance he'd been given, Jack pulled Nathan into his arms and kissed him like he would never let him go, and after a moment's hesitation, Nathan kissed him back just as ferociously.

When they finally separated, all Jack could feel was the happiness bubbling through him, and all he could see was the love shining back at him through Nathan's desire-darkened eyes.

It was more than he ever dreamed of having, and as the others rushed in to welcome Nathan back, Jack knew this was just the beginning of the rest of their lives together.

END


End file.
